A radio frame in a Long Term Evolution (LTE) system includes frame structures of a Frequency Division Duplex (FDD) mode and a Time Division Duplex (TDD) mode. The frame structure of FDD mode is shown in FIG. 1, one radio frame of 10 ms is composed of 20 slots with numbers 0˜19 and the length of each slot being 0.5 ms, and a subframe i of 1 ms is composed of slots 2i and 2i+1. The frame structure of TDD mode is shown in FIG. 2, one radio frame of 10 ms is composed of two half frames each of which has a length of 5 ms, one half frame includes 5 subframes each of which has a length of 1 ms, and subframe i is defined as two slots 2i and 2i+1 each of which has a length of 0.5 ms. In the above two frame structures, for a Normal CP (Normal Cyclic Prefix), one slot includes 7 symbols each of which has a length of 66.7 us, wherein a CP length of the first symbol is 5.21 us and the length of each of the other 6 symbols is 4.69 us; for an Extended CP (Extended Cyclic Prefix), one slot includes 6 symbols, the length of each of the 6 symbols is 16.67 us.
The version number of the LTE corresponds to R8 (Release 8), and the version number to which an additional version of the LTE corresponds is R9 (Release 9); while, for the future LTE-Advance, its version number is R10 (Release 10). The following three downlink physical control channel are defined in the LTE: a Physical Control Format Indicator Channel (PCFICH), a Physical Hybrid Automatic retransmission Request Indicator Channel (PHICH) and a Physical Downlink Control Channel (PDCCH).
Wherein, the information carried in the PCFICH is used to indicate the number of Orthogonal Frequency Division Multiplexing (OFDM) symbols of the PDCCH transmitted in one subframe, the OFDM symbols of the PDCCH are transmitted in the first OFDM symbol of the subframe, and the frequency position is determined by a system downlink bandwidth and a cell Identity (ID).
The PHICH is used to bear acknowledgement/negative-acknowledgement (ACK/NACK) feedback information of the uplink transmission data. The number of the PHICHs and time-frequency position can be determined by a system message and a cell ID in a Physical Broadcast Channel (PBCH) of a downlink carrier at which the PHICH located.
The PDCCH is used to bear Downlink Control Information (DCI) which includes: uplink/downlink scheduling information, and uplink power control information. The DCI format are classified as follows: DCI format 0, DCI format 1, DCI format 1A, DCI format 1B, DCI format 1C, DCI format 1D, DCI format 2, DCI format 2A, DCI formats 3 and DCI format 3A, and so on; wherein:
DCI format 0 is used to indicate the scheduling of a Physical Uplink Shared Channel (PUSCH);
DCI format 1, DCI format 1A, DCI format 1B, DCI format 1C and DCI format 1D are used to different modes of a PDSCH codeword scheduling;
DCI format 2, DCI format 2A and DCI format 2B are used to different modes of space division multiplexing;
DCI formats 3 and DCI format 3A are used to different modes of power control instructions of the Physical Uplink Control Channel (PUCCH) and the PUSCH.
The sizes of DCI formats 3 and 3A are identical with the size of DCI format 0. In the DCI format 3, two consecutive bits are used to indicate Transmit Power Control (TPC) commands of the PUCCH and the PUSCH, and a high layer signaling tpc-Index designates an initial position of the TPC command of a user; while, in the DCI format 3A, 1 bit is used to indicate TPC commands of the PUCCH and the PUSCH, and a high layer signaling tpc-Index designates an initial position of the TPC command of a user.
Specifically, the DCI format 3 uses 2 bits to transmit the TPC commands for the PUCCH and the PUSCH, and the following information is indicated by the DCI format 3:
TPC command 1, TPC command 2, . . . , TPC command N
Wherein,
      N    =          ⌊                        L                      format            ⁢                                                  ⁢            0                          2            ⌋        ,Lformat0 is equal to the size of the DCI format 0 before a Cyclical redundancy check (CRC) is added, which includes any additional bit. The parameter tpc-Index given by the high layer signaling is used to designate an index of the TPC command of a user.
If
            ⌊                        L                      format            ⁢                                                  ⁢            0                          2            ⌋        <                  L                  format          ⁢                                          ⁢          0                    2        ,one bit 0 will be added into the DCI format 3.
Specifically, the DCI format 3A uses 1 bit to transmit the TPC commands for the PUCCH and the PUSCH, and the following information is indicated by the DCI format 3A:
TPC command 1, TPC command 2, . . . , TPC command M
Wherein, M=Lformat 0, and Lformat 0 is equal to the size of the DCI format 0 before a CRC is added, which includes any additional bit. The parameter tpc-Index given by the high layer signaling is used to designate an index of the TPC command of a user.
Because a LTE-Advanced network needs to be able to access LTE users, the operation frequency band of the LTE-Advanced network needs to cover the present LTE frequency band. However, on that frequency range, there have been no allocated consecutive frequency spectrum bandwidth of 100 MHz, so a direct technology which the LTE-Advanced needs to solve is to aggregate several consecutive component carriers (frequency spectrum) allocated on different frequency bands together by adopting a Carrier Aggregation technology, to form the band width of 100 MHz that the LTE-Advanced can uses. With regard to the aggregated frequency spectrum, it is divided into n component carriers (frequency spectrum), and the frequency spectrum in each component carrier (frequency spectrum) is consecutive.
In the 57th bis conference of the 3GPP, setting a user equipment downlink component carrier set (UE DL Component Carrier Set) and a user equipment uplink component carrier set (UE UL Component Carrier Set) are passed. The UE DL Component Carrier Set includes some component carriers, and the user needs to receive the PDSCH on these component carriers in the downlink; and the UE UL Component Carrier Set includes some component carriers, and the user needs to receive the PUSCH on these component carriers in the uplink.
In the LTE-Advanced system, the adoption of the carrier aggregation makes a downlink component carrier may correspond to multiple uplink component carriers, which is different from the case that only one downlink carrier corresponds to one uplink carrier in the LTE system. At the moment, a method for transmitting a uplink transmission power control command also exists some differences. At the present stage, there is no clear scheme and definition on the method for transmitting the uplink transmission power control command in the LTE-Advanced system, thereby bringing inconvenience to the practical application.